My favourite ranged weapon is (believe it or don't) the Frog Gun. I like that the flies cause damage both outgoing and incoming, and it doesn't exhaust my energy bar after only one or two shots. The only place it is less than optimum is during the Octopus boss fight, since it often can't reach the arm jewels.

I really like the upgraded blaster, just for the sound alone. It's that good. Tesla gun is also very satisfying to use. From melee weapons I really like the antenna. It's short, but it zaps and stuns people! Also the mace. Not the best weapon, but It has a good feeling of weight and it is fun to crush enemies with it (especially jump attack).

For multiple enemies, I'm gonna go with an initial shot from the Badass Black Hole Gun - this can suck lots of health from nearby enemies, often wiping them out in one go - followed by multiple shots from BFRPG to finished them off; it also has splash damage. Favourite melee weapon has to be the Kraken Tentacle because of its long reach and formidable strength.